The present invention relates to a semiconductor module and an inverter device.
There exists an inverter circuit for driving an electric motor for a hybrid vehicle, an electric vehicle, or the like. A semiconductor module that includes a switching element that forms the inverter circuit has a high heating value, and furthermore, requires downsizing. Therefore, a water-cooling system is often used as a cooling structure of the semiconductor module. As the configuration of the semiconductor module having such a water-cooling system, Japanese Patent Application Publication No. JP-A-2004-349324 (pages 6 and 7, and FIG. 5) mentioned below discloses a configuration shown in FIGS. 14A, 14B and 14C for example. FIG. 14A is a plan view, FIG. 14B is a side view, and FIG. 14C is an elevational view. A semiconductor module 101 shown in FIGS. 14A, 14B and 14C includes a base plate 102 in which a fin 103 in stripe form is formed on a back surface, and six substrates 104 placed on an upper surface of the base plate 102. On the lower surface of the base plate 102, a water path cover (not shown) is provided to contact a bottom surface of the fin 103 (surface on a lower side of the fin 103 in FIG. 14B), whereby each coolant flow path 105 is formed between the plurality of fins 103. Therefore, in the semiconductor module 101, a coolant flow direction D is the longitudinal direction (horizontal direction in FIG. 14B) of the base plate 102. Six substrates 104 placed on the base plate 102 are arranged in line in the coolant flow direction D.
On each substrate 104, two each of an insulated gate bipolar transistor (IGBT) element as a switching element 106 and a diode element 107 are arranged. A connection terminal area 108, in which a wire bonding for electrically connecting the elements 106 and 107 and a control substrate (not shown) on each substrate 104 is performed, is arranged adjacent to each substrate 104. On the substrate 104, two switching elements 106 and two diode elements 107 are arranged alternately in line in a perpendicular direction with respect to the coolant flow direction D. The connection terminal area 108 is arranged on a side opposite to a side in which a pair of substrates 104A and 104B face each other in the coolant flow direction D.